Excavating machinery



Patented Feb. 7, 1922.

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EXCAVATING MACHINERY.

APPLICATION HILED MAYIO, 1920.

1,405,796. Patented Feb. 7, 1922.

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B. A. MIDDLEMISS.

EXCAVATING MACHINERY. I APPLICATION FILED MAY 10, 1920.

Patented Feb. 7, 1922.

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EX'CAVATING MACHINERY.

APPLICATION FlLED MAY 10. 1920.

Patented Feb. 7, 1922.

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1,405,796. APPLICATION FILED MAY 130, 1920. 7

5 SHEETSSHEET 5- UNITED STATES PATENT cranes.

BRUCE A. MIDDLEMISS, or CHUQUQUI CAMATA, CHILE, AssIeNoa TO CHILE EXPLO- aATIoN COMPANY, or NEW YORK, N. Y., A CORPORATION or NEW YORK.

EXCAVATIN G MAGHINERY.

- Application filed'May 10,

do hereby declare the following to be a' full, clear, and exact description of the invention, such as will enable others skilled inthe art to which it appertains to make and use the same. This invention relates to excavating machinery designed for open workings, but applicable to mines and the like, and as well to sub-aqueous work.

. One object of this invention is to provide an excavator of largev capacity in which there shall be no swinging of the boom or corresponding part after the shovel has been filled with material, thus saving the time consumed by apparatus of this sort in swinging the shovel from loading position to unloading position and back again, which is recognized by shovel operators as consuming about 75% of the time. Another object is to provide an easy and graduated discharge from the shovel into the car, scow, or corresponding dump, and associated withthis advantage is that of providing a single discharge orifice under. which the dump shall be located and avoid the necessary changes in position of the car into which the material is dumped.

A still further advantage is the economy in operating power whereby reason of the avoidance ofthe excessive power incident to the swinging action in handling immense quantities of material in the dipper, there is simply necessary the power to raise the dipper and load vertically. For instance, where the usual machines of today have as a maximum about twelvetons handledin each shovelful, the present mechanism is capable of taking care of and discharging without damage to the dump a load of 20 cubic yards to the shovel, or thirty-five tons.

Another advantage is that by the construction present in this apparatus there is a considerable saving in damages to the loaded vehicle. For instance, it is not uncommon in swinging large booms and shovels for the car to'be struck sidewise and tipped from the track. In the use of this invention the contents of the dipper are dis- Specification of Letters Patent.

Patented Feb. 7, 1922.

1920, Serial No. 380,066.

handle presents a force to be resisted which is almost insurmountable. Again, in digging, careless shovel men will start'to swing the load before the dipper is entirely out of the bank and thus introduce a tremendous stress upon the boom construction at the handle end. The manifest advantage of avoiding these circumstances by the construction of this invention is a very important one. i

' Other advantages will become apparent in connection with the following description of the drawings forming a part of this specification; in which v Fig. 1 shows an elevational view partly in section with a dipper at work in a plane transverse to the tracks on which the excavator is positioned;

Fig. 2 is a plan view of the excavator shown in the same position;

Fig. 3 is a rear elevation of the excavator;

Fig. 4 is a plan view of the dipper and portions of its handle and chute;

Fig. 5 is a. side elevation of the dipper and a portion of its handle;

Fig. 6 is a detailed sectional view on the line 6-6 of Fig. 7 and shows the means for mounting and manipulating the inner end of the handle;

Fig. 7 is a detailed elevational view of a portion of the boom adjacent the inner end of the handle;

Fig. 8 is a diagrammatical plan view of the operating mechanism for turning the excavator, for raising the boom and manipulating the dipper; and

Fig. 9 is an elevational view of the rear of the operating mechanism of Fig. 8, showing the arrangement of the operating mechato permit the passage of loading vehicles.

An operators cab 18 is located upon one ,side of the body .and provides the necessary outlook upon the tracks 10 and! 11, and contains control devices for the motor mechanism 19 connected by sprocket chain or other suitable driving means 20 with the driving gears on the trucks 16. The body 15 and its supporting pillars 17 are constructed of suitable steel shapes and plates,

and it has an upper floor 25 and a ceiling 26 therebelow supporting the motors 19 and the appurtenant parts. Extending between the floor 25 and the ceiling 26 is a-circular hopper 27 in the form of an inverted frustum of a cone, which in addition to its soft steel surface plates has lining plates 28 of manganese steel or other similar wear resisting material arranged as parts of its conical surface. The hopper 27 is located at the center of the carriage 15. In order to prevent direct,falling of large rocks into the dump, a stationary buifer 31 having a supporting frame work 32 and a wear resisting cover plate 33 of manganese steel,

2 or the like, is suitablypositioned at the upper entrance to the hopper. A supplemental swinging buffer 34 having a support 35 on each side thereof is located above the stationary buffer 32 so as to slow up the descending material and reduce the shock on bufl'er 31 and the car below. A cover plate 36 of manganese steel is formed to the shape of the bufier and replaceably attached thereto. In order to enclose the buifers and pre-* vent dust from passing to the interior of the cab a hood extends along the sides of the hopper and from the floor of the cab to the roof thereof and encloses the dis charge space- "A turn table 37 is carried above the floor 25 of the body and is turned on double flanged rollers 38 runningon a track 39 upon the floor 25, and motive power .is' applied to the turn table by means of a large exterior gear 40 actuated in a manner to be later described. In order to maintain the turntable and the cab at the axis Turn table 37 forms a foundation member ing as it does the cab and machinery, the

stiff legs 45 and the A frame 46, the boom 47 the shovel 48 and the'shovel handle 49, together with the safety cables 50 and,the boom hoisting cables and apparatus 51. Other parts not specifically mentioned are likewise carried by the turn table, all forming a considerable weight and requiring a staunch construction to be made. of shapes and plates, the design of which need not be elaborated upon.

As substantially the usual practice is employed in the stiff legs, the A frame, the safety cables and'the boom hoisting apparatus, it is undesirable to describe them. in de- 7 tail, as they are carried in the usual mountings joined to the turn table or their connected parts in a well known manner. The boom 47 is connected to the turn table which carries the boom base member 52 into which enters the pivot member 53 whereby the thrust plate 54 and the base plate 52 are" pivotally connected. The thrust plate 54 extends across the end of the boom which is formed at each side of twobox girders 55 of suitable steel construction separated from each other a substantial distance, and carrying therebetween and pivotally. attached thereto achute 56. The box frame members 55 at their upper ends have an elbow 57 serving to render rigid the box girders at their upper and reduced ends,

and also withdrawing the upper ends from the bank to be removed.

The box girders carry bearings for a shaft 58, and this shaft has secured thereto two sets of sheaves 59 and 60. The outer sheaves 59 have winding thereon cables connectedat their other ends with winding mechanisms, and the sheaves 60 are connected by cables directly to the dipper. The cables extending to the winding mechanism andthose extending to the dipper are wound in opposite directions, and it will be evident that by-vary- .ing the relative size of the sheaves, avariation in relative speed between the movement.

of the cables may be obtained.

Intermediate the foundation plate 52 and the elbow 57 is located a second shaft 61 extending across the lower edge of box girders 55 of the boom 47, which may be termed the handle manipulating shaft.

Shaft 61 and its mountings and adjacent parts are, shown in detail in Figs. 6 and 7. Bearing members 62 which are supported by extensions 63 secured to the vertical sides of the boom members 55 have alined bearings for receiving the shaft 61. Spanner nuts retain the shaft in the bearing member 62.

Intermediate the bearings 62 on each side of the boom gears 64 are interposed, the same being fast to the shaft 6l-by means of keys 65. Gears64 are shown with an insert 70 of wear resisting material suclf as manga-.

I ings and serve the same purpose. The gear inserts 70 co-act with corresponding gear inserts 71, on a rack 72 carried by a hydraulic cylinder 73, which will be later described in detail. The power transmitted to the gear 64 is carried to a similar gear 74 also keyed to shaft 61 and having similar inserts 70 which in turn co-act with gear inserts 71 upon a rack 75 fastened on the bottom of each side of the dipper handle49. The power of the'gear 74 is thus transmitted to the rack 75 and manipulation thereof up and down and in and out is thus secured.

The handle of the dipper to which the racks 75 are connected is constructed as shown in cross section in Fig. 6, of a lower plate 76 extending between two side members 77 which are built up of a thick metal plate 78, a stick of timber 79 and a thick top plate 80 forming a trough like member which car ries a wear resisting inner lining 81 or chute formed of a section which extends upon both inner sides of the handle and across the bottom. These may be made of wear resisting material being suitably fastened to the other parts of the dipper handle, it being understood, of course, that aside from the member 81 each side of the dipper handle is a dupli cate of the other.

The upper plate 80 has a longitudinally extending rib 82 on its upper face, of a length corresponding to that of the rack 75. Grooved pulleys 83 are carried by substantially triangular saddle members 86, which are arranged at opposite sides of the dipper handle, between the gears 74 and the adjacent bearing 62. The saddle members carry bolts 84 upon which the pulleys 83 are arranged, the bolts being held in place by nuts 85. Each of the saddle members has a bearing upon the shaft 61, and referring to Figure 6 it'will be seen that the said members have lateral flanges extending above the pulleys 83. The purpose of the saddle members is to aline the dipper handle and maintain the racks 75 in contact with the gears 74.

The bearing members 62 are extended downwardly along the lower surface of the boom 47 and carry on each side a pivot memher 190 which serves to supportthe upper end of the chute 56, the lower end of which rests upon the upper edge of the hopper guard ring 14, and slides thereupon depending upon the movement of the boom 47 when it is lowered after cessation of the digging operations for any length of time. 'The lower chute 56 has an outer trough madeup-of steel plates and shapes connected to which in section is the inner manganese sheet chute similar to chute 81 of the dipper handle. These parts are not shown in detail as it thought unnecessary to do so, as the construction of the lower chute is plain from the foregoing consideration of the chute If desired formed in the dipper handle. the construction of the lower chute may be altered as necessary.

The dipper handle substantially as described extends outwardly to dipper 48,

where as shown in Figs. 4 and 5 connection is made with the two side castings 90 which are securely bolted to the contiguous end portions ofv the dipper handle. As shown in Fig. 6 the sides 90 are ribbed for the sake of rigidity and their forward portions are joined again to the digging edge 91 of the dipper which carries upon its edge reversible teeth 92, both parts obviously being of wear resisting material and likewise built for rigidity. The bottom of the dipper is formed by a heavy casting 93 suitably connected at the inner end to the dipper handle, at its edges to the sides 90 and at thefront to the dipper front 91. It should be noted that the bottom 93 is positioned at an angle to the bottom surface of the chute 81. Fastened upon the dipper front are the bail connections 94 supplied on each side of the dipper and apertured at 95 to receive a con-- necting pin joining a .bail 96 thereto. Connected to bail 96 is an equalizer 97 necessary on account of the use of double cables 98 which extend from the equalizer to the inner sheaves 60 at the head of the boom. The cable 98 is fiat and the upper end is fastened tow the bottom of the slot in sheaves 60 and coils thereon between the sides 66 on said sheaves. As before stated,- thev sheaves 59 and 60 are rigid with the shaft 58, and the said sheaves have marginal flanges 66 and 159, respectively. The cables 98 wind upon the sheaves 59, and other cables 99 wind upon the sheaves 60, but in the opposite direction to the cables 98. The arrangement is such that when the cables 99 are unwound, the cables 98 are wound up, and it will be noticed that the sheaves 60 are of greaterdiameter than the sheaves 59, so that the cables 98 move faster 99.. The cables 99 are'flat corresponding to cables 98, there being four of them instead of two of the latter and they extend to a guide sheave or pulley 100' positioned in a pillow block 101 located at the upper surface of the boom 47 at or adjacent to the elbow 57. From the pulley 100 the cables 99 extend to the cab or house and to sheaves there: in actuated in the manner described later.

The inner'end of the dipper handle 49 receives its manipulation or driving by means of movement of the sliding cylinders 73 on each side" of the boom sliding upon a sta:

.in winding and unwinding than the cables v interior of the piston rod while hollow for most of its length is plugged when the piston is fastened thereto, there being connections on each side of the plug with the -.respective sides of the piston to slide the cylinder in one direction or the other depending upon the position of the proper control valve trol head 123 in the operators cab 124. The

in the operators cab. The hollow piston rod is piped to the accumulator 122 by the pipe 102 through a set of jointed short pipes 103 .from which connection is made directly to the boom end of the piston and through the pipe 104 to the 11 per end of the piston rod. The valve control ing the flow to one or the other ends of the piston rod is located in the jointed pipe 103 and operated fromthe concylinder carries on its top 'a fixedbearing edge 108 in contact with the guide pulleys 109 having rims 110 and carried upon shaft 111 supported at its ends in bearings 112 fast to a transverse member 113 within the I boom, there being a plurality of pulleys 109 positioned throughout the extent of the guide bar 108 so as to suitably guide the cylinder [in its travel. In'order tosupport the cylinder 7 3 from below there is positioned on the lower edge of the boom members 55 a short shaft 114 upon which turn pinions 115 having teeth the size of those on the rack 72 and co-acting therewith so as to forma carrying means for said cylinder. As the cylinder 73 may be traveled along the boom for some distance pinions 115uare distributed from very near the lower end of the boom upwardly to some distance above the inner end of the dipper handle 49. Of course, other means may be provided for actuating the inner end'of the handle, it-being" intended to describe only one method therefor. v

It should be noted that when the dipper 48 is in the dot and dash line position of Fig. 1 or adjacent. thereto, after the dipper 1 has been raised a short distance, the handle '49 and its chute 81 form in effect the back edge of the dipper, at least serve to retain 1 machinery in Fig. 1. l

- i Reference to Fig.2 will show that the the material therein in the lowermost position while when the dipper is in the full line position the dipper becomesa portion of the chute, the material sliding along the bottom thereof which isrin' reality an extension of the chute proper. Because of the fact that the dipper and its controlling mechanism is mounted on a turn table, it will be obvious.-

that the dipper may be swung to work ahead of the track 10, or ateither 'sidethereof, swinging through an angle of more than 180. Thus the excavator can clear a foundation for its track and swing to either side of the track,.meanwhile depositing the excavated material in the dump car in thelsame' manner as that shown in the position of the upper end of the lower chute 56 is wider than the lower end, and the width is such as to receive upon and within the upper end the inner end of the chute 81; Consequently when the handle and the dipper are raised to an angle of30 to the horizontal a gradual discharge of the dry material from the dipper 48 will occur, and therefrom into the chute 56 during the continuation of the movements of the dipper and handle into their uppermost position which is about 45 handle may be halted in any desired intermediate positlon so as to graduate the discharge into the lower chute 56, and thus shocks upon the lower part of the excavator and the dump car are avoided. It will be noted that this operation starts, continues and finishes all in the same plane, which is that of .to the horizontal. Qf course, if desired the the boom 47, and that there is no time con sets of power units comprising motor 120.

and two pumps 121 which supply water or other fluid to the. accumulator 122 up to a defined pressure,after which the pumps simply churn the water, one motor turning continuously while in use and a valve or valves being manipulated from a control head 123 in the operators cab 124 located midway on one side of the cab, the valve serving to connect the accumulator with the desired hydraulic cylinder. At each side of the cab are hydraulic cylinders 125 fixed in position and carrying a plunger 126 joined to across head 127 carrying thereon a set of sheaves 128 around which a cable 129 passes. Slides 130 for the'cross head 127 are provided. .The

cable 129 passes between sheaves 128 on each side of the cab around guide sheaves 131 and 132 and from thence to sheaves133 around which there are a plurality of cables, and

ve which is aturn table operating gear 40 contacting with and drivingz the circular gear 21 on the turn table. The piston 126 of the respective cylinders move in the opposite direction so that upon the outer movement of one,'the cable 129 shall-be traveled in one direction and drive'thegear 40 and the circular gear 21 in one direction, whereas uponthe reverse the' turn table and gear 21 are driven in theopposite direction to swing the turn table and cab. At the end of the movement of the turntable locking means actto retain it and connected parts-in a fixed I position so thatno inovement thereof shall later ensue. The movement of the cross head 127 is utilized in raising. the boom when for any reason digging operations are to be suspended and it is not desirable to retain the boom in operative position. The cables 51 for hoisting the boom extend between a set,

' of sheaves 43 and corresponding sets of power is thus-supplied to the boom hoisting cables upon the movement ofthe plunger 126, the cable 129 being disconnected for the time being. Once the boom has been raised to position the safety cables 50 are fastened at their respective ends at the head of the boom 47 and the plate44 and the cables 51 disconnected and stowed away in a convenient manner.

A similar installation is employed for the actuation of the boom cables 99. A pair of cylinders 140 operated by a valve similar to that already mentioned carry plungers 141 which. have mounted at their outer ends a cross head 142 carrying sheaves 143 around which the cable 99 passes after being fastened at the end to the foundation of the cylinder 140. Cross heads slides 144 are provided upon which cross heads 140 move. Upon the outward movement of the plun gers 141 the sheaves 143 are caused to travel with their cross heads and thus exert a pull upon the cables 99 which pass over guide pulleys 145 to the guide pulley 100, and from thence fto the inner sheaves 59, the outer end 0 the dipper cables 'being fast to sheaves 60 coiling thereupon between the sides in the manner described.

' Reference to Figs. 8 and 9 will show for the most part the mechanism above described, and there is also included the boom cylinder 73 and its piping to which water under pressure from the accumulator is admitted upon manipulation of the valve in the dipper operators cab 124 The tanks 150 piped to the accumulator 122 supply the water lost by leakage,.and also serve as settling tanks for'the dischargedwater from the hydraulic cylinders described, and per.- mit the air introduced to the water in the hydraulic cylinders to disengage itself from- ,the water before'being used again.

' In order to counterbalance theweight of the boom, the dipper, andother heavy parts,

counterbalance boxes 151 are provided a switch in the operating head in the cab, causing the motor to function and drive the truck. Thereafter, when the boom has been erected and fastened the dipper is driven downwardly into the bank by manipulation of'the boom cylinder, which acting upon the rack from the control head in the shovel mans cab, the bottom of the dipper handle controls the elevation ofthe inner end of the handle. In conjunction with the manipulation of the inner end of the handle the cable from the boom head tothe dipper is hauled up by the man in the cab controlling the hydraulic pressure from the control head in the cab. It is apparent that the dipper and the dipper handle are manipulated jointly until the dipper is clear of the bank, at which time the inner end of the dipper handle should be positioned so that the inner end of the chute therein shall sufliciently overlap the lower chute extending to the hopper. After this position is obtained the discharge of the dipper is accomplished by simply continuing the lifting action of the cable until the dipper handle is about 30 to the horizontal. The speed of discharge from this point may be controlled by the rate of lifting of the dipper, as usually when once started it will continue and may be controlled to a nicety by the gradual raising of the dipper. A

sudden discharge may also be obtained by r the rapid hoisting of thedipper.

Before the dipper has reached its highest position thecontents will be discharged in most cases, at which time the descent of the dipper will be permitted and the co-related manipulation of the handle be started. The discharged material when all out of the dipper handle chute is continued into and through the lower chute against the swing ing bufier being diverted thereby, so that a comparatively gentle stream of excavated material passes through the chute and down through the hopper into the dump. Large rocks are prevented from dropping from the end of the chute into the dump by reason of the fixed buffer permitting a large portion of loose excavated material to fall into the dump capable of absorbing a large portion of the shock which would otherwise occur by direct -con-- tact with the interior of the dump.

While the preferred embodiment of the invention has been described hereinabove and illustrated in the drawings as afore s said, no limitation to the precise structure comprised in such disclosure is contemplated, except 111 so far as ma necessarily be imposed by the language 0 the a pended claims, since the invention is o vlously boom and relatively fixed with respect to the boom for moving said handle with respect to said means and the boom, a chute carried by said handle and discharging its,

' contents into the chute carried by the boom,

a dipper on said handle manipulated by connections withsaid boom and loading and discharging into the chute in the handle.

2. In an excavator, a boom, a handle havmg a dipper supported by the boom, the handle formingv a discharge chute for the dipper, and means on the 'boom and rela-,-

tively, fixed with respect thereto and engaging the handle for moving said handle with respect to said means and the boom.-

3. In an excavator, a boom, a hopper at theinner end of the boom, a handle having a dipper supported by the boom, the handle forming a discharge chute for the dipper, a

. guide chute supported? by the boom and delivering'to the hopper, the handle delivering to the chute, and means on the boom and fixed relatively to the boom for moving said handle with respect to said means and the boom.

4. In an excavator, a boom, a handle havmg a dipper supported by the boom, the handle forming a, discharge chute for the dipper, and means on the boom and relatively fixed with respect thereto and engagmg the handle for moving said handle with respect to said means and the boom, a

plurality of rigidly connected reels supported by-the boom, flexible members connected with the dipper and winding on sundry of the reels, other flexible members winding on others of the reels in the opposlte direction tothe first named members whereby when said members are moved in one direction the first named members will be moved in the opposite direction.

5. In an excavator, a boom, a hopper at the Inner end of theboom, a handle having a dipper supported by-the boom, the handle forming a discharge chute for the dipper,

a guidechute supported by the boom and dehvermg to the hopper, the handle del1vermg to the chute, and m ans on the boom and fixed relatively to t e boom for moving said handle with respect to said means and the boom, said means comprising racks rigid with the handle, pinions on the boom, and fluid pressure controlled means for moving the racks.

6. In an excavator, a boom,--'a hopper at the inner end of the boom, a handle having a dipper supported by the boom, the handle forming a discharge chute for the dipper, a guide chute supported by the boom and delivering to the hopper, the handle delivering to the chute, means on the boom and fixed relatively to the boom for moving said handle with respect to said meansand the boom, and a turn table supporting the boom and rotatable about the hopper. r,

7. In an. excavator, a wheeled supporting carriage, a turn table mounted to rotate on the carriage, a boom on the turn table, a hopper at the axis of the table, a gulde chute supportedby the boom and delivering to the hopper, a handle supported by the boom and having a dipper and forming a discharge chute for the dipper and delivering to the guide chute, means on the boom and relatively fixed with respect thereto and I engaging the handle to move the same with I respect to the boom, a fixed buffer at the opposite side of the hopper from the chute and a swinging bufi'er arranged between the fixed buffer and the guide chute.

. 8. In an excavator, a boom, a hopper at the boom and having a dipper at the outer end thereof, and forming a discharge chute for the dipper, a guide chute supported by the boom to which the handle delivers,

and delivering tq the hopper, and means on t the boom and relatively fixed with respect thereto and engaging the handle for moving the handle to force the dipper into the ground.

9. In an excavator, a boom, a hopper at the foot of the boom, a handle supported by the boom and having a dipper at the outer end thereof, and forming a discharge chute for the dipper, a guide chute supported by the boom to which the handle delivers and delivering to the hopper, and means on the boom and relatively fixed with respect there-' to and engaging the handle for moving the I the foot of the boom, a handle supported by handle to force the dipper into the ground,

a turn table rotatable with respect to the hopper on which the boom is mounted, sheaves having guided movement on the turn table, flexible members connected with the boom and with the turn table and pass ing overthe sheaves, and fluid pressure controlled means for movingthe sheaves to raise and lower the boom.

10. In an'excavator, a boom, a dipper handle, a dipper thereon, connections be- I tween the boom and the handle for manipu lating thediandle and the dipper, a chute on said handle receivin the contents of the dipper, a chute on t e boom receiving the A discharge from the first named chute, and

bumpers interposed in the path of the material passing along said chutes, one of which is movable to a plurality of positions. 11. In an excavator, a body, a hopper, a bumper adjacent thereto, a dipper, connecttions between the dipper and the hopper, said bumper directing the discharge of large masses of material directly to the hopper and lessening the force of discharge through the hopper.

12. In an excavator, a body, a hopper, a boom, a dipper, a dipper handle, means in the boom and the dipper handle joining the hopper to the dipper, and means adjacent thereto and contacting with the contents thereof.

13. In an excavator, a body, a hopper, a boom, a dipper, a dipper handle, means in the boom and the dipper handle joining the hopper to the dipper, and means adjacent thereto and contacting with the contents thereof, and retarding the progress of the contents.

14:. In an excavator, a dipper having a handle forming a chute through which the dipper discharges, a hopperinto which the chute discharges, and a bumper between the having a handle forming a chute deliverlng to the hopper, means for operating the dipper, and bumpers interposed in the path of the material passing along the chute, one of said bumpers being adjustable for the purpose specified.

16. In an excavator, a dipper having a handle forming a chute through which the dipperdischarges, means for operating the dipper, a hopper to which the handle delivers, a fixed bumper opposite the delivery end of the chute and supported to move with the dipper when said dipper swings in the horizontal plane whereby to retain its position opposite the delivery end of the chute, and a movable bumper between the chute and the fixed bumper and adjustable with respect to the chute to close or open the same, and to graduate the discharge therefrom.

In testimony whereof I aflix my signature.

BRUCE A. MIDDLEMISS." 

